Re: [PATCH v4 06/28] iommu/arm-smmu-v3: Split code with hyp

Mostafa Saleh
2025-09-16T14:11:07Z

On Tue, Sep 09, 2025 at 03:23:14PM +0100, Will Deacon wrote:
> On Tue, Aug 19, 2025 at 09:51:34PM +0000, Mostafa Saleh wrote:
> > The KVM SMMUv3 driver would re-use some of the cmdq code inside
> > the hypervisor, move these functions to a new common c file that
> > is shared between the host kernel and the hypervisor.
> >
> > Signed-off-by: Mostafa Saleh <smostafa@google.com>
> > ---
> > drivers/iommu/arm/arm-smmu-v3/Makefile | 2 +-
> > .../arm/arm-smmu-v3/arm-smmu-v3-common-hyp.c | 114 ++++++++++++++
> > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 146 ------------------
> > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 44 ++++++
> > 4 files changed, 159 insertions(+), 147 deletions(-)
> > create mode 100644 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common-hyp.c
> >
> > diff --git a/drivers/iommu/arm/arm-smmu-v3/Makefile b/drivers/iommu/arm/arm-smmu-v3/Makefile
> > index 493a659cc66b..1918b4a64cb0 100644
> > --- a/drivers/iommu/arm/arm-smmu-v3/Makefile
> > +++ b/drivers/iommu/arm/arm-smmu-v3/Makefile
> > @@ -1,6 +1,6 @@
> > # SPDX-License-Identifier: GPL-2.0
> > obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o
> > -arm_smmu_v3-y := arm-smmu-v3.o
> > +arm_smmu_v3-y := arm-smmu-v3.o arm-smmu-v3-common-hyp.o
> > arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_IOMMUFD) += arm-smmu-v3-iommufd.o
> > arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o
> > arm_smmu_v3-$(CONFIG_TEGRA241_CMDQV) += tegra241-cmdqv.o
> > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common-hyp.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common-hyp.c
> > new file mode 100644
> > index 000000000000..62744c8548a8
> > --- /dev/null
> > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common-hyp.c
> > @@ -0,0 +1,114 @@
>
> Given that this thie is linked into both the kernel and the hypervisor
> objects, I think I'd drop the '-hyp' part from the filename. Maybe
> something like 'arm-smmu-v3-lib.c' instead?
>

Yes, that makes more sense, will do that.

Thanks,
Mostafa

> Let the bike-shedding begin!
>
> Will